In the aviation industry, there is a very grave concern about an aircraft fire due to the rupture of the fuel lines following a survivable crash of the aircraft (i.e., an event whereby the aircraft crashes with most if not all of the aircraft occupants surviving the crash event). The current airworthiness standards for fuel lines installed on transport category aircraft (14 CFR §25.993(f)) requires that each fuel line within the fuselage of the aircraft must be designed and installed to allow a reasonable degree of deformation and stretching without leakage. Aviation authorities have therefore indicated that a certain deflection of a duct in a guillotine-like test is acceptable to show compliance with such requirement.
One prior proposal for aircraft fuel line compliance is known from U.S. Patent Publication 2013/0181441. According to this prior proposal, an anti-buckling coupling device for fuel double-walled piping is provided. The proposed coupling is intended to be installed at the location of the fuel line anchor points, so that the weight of the coupling is supported by the aircraft structure and not by the fuel line piping. Thus, these proposed couplings are linked to the ducts by means of a groove connector, or sphere cylinder, i.e., a connector that combines a swivel connection and a sliding connection along the longitudinal axis of the duct.
Improvements to aircraft fuel system components which comply with airworthiness standards for fuel lines installed on transport category aircraft for both survivable crash and lightning strike events are however still needed. It is towards fulfilling such needs that the embodiments disclosed herein are directed.